Performance Enhancement of Asymmetrical Double Gate Junctionless CMOS Inverter With 3-nm Critical Feature Size Using Charge Sheet

Abstract

In this paper, after calibrating the models and parameters used in the simulations based on experimental data, by using the opposite doping in the channel and between the gates in an asymmetric double-gate junctionless (JL) transistor with the 3nm gate length, a charge sheet (CS) was created. The results showed that, due to creating CS in the middle of the channel, the horizontal electric field was increased, thus more major carriers were depleted from the middle of the channel. With the analysis of the $\text{I}_{\mathrm{ DS}} - \text{V}_{\mathrm{ GS}}$ diagrams at different temperatures, it was concluded that in the CS JL MOSFET, while the ON-state current is very close to compared that in the JL MOSFET (same structure without CS), the drain leakage current has decreased by around 103. Furthermore, the $\text{I}_{\mathrm{ DS}} - \text{V}_{\mathrm{ DS}}$ diagram showed that the drain current in the CS JL MOSFET was much less affected by the drain voltage compared to that in the JL MOSFET. Also in AC analysis and at 1MHz frequency, by using CS the parasitic capacitances were reduced. Due to the improvement obtained in the presence of the charge sheet, the proposed structure was used in designing an inverter. The results showed that in the presence of the charge sheet, logical high input range, and logical low input range were increased, and also, noise margin low (NML) and noise margin high (NMH) were improved.

Keywords

• Junctionless transistor
• MOSFET
• CMOS
• inverter
• charge sheet
• DC analysis